Field of the Disclosure
The present disclosure relates to an organic light emitting display apparatus, and more particularly, to a top emission type organic light emitting display apparatus.
Discussion of the Related Art
Organic light emitting display apparatuses are self-emitting apparatuses and typically have low power consumption, a fast response time, high emission efficiency, high luminance, and a wide viewing angle.
The organic light emitting display apparatuses are typically classified into a top emission type and a bottom emission type, based on a transmission direction of light emitted from an organic light emitting device. In the bottom emission type, a circuit element is disposed between an emission layer and an image displaying surface, and for this reason, an aperture ratio is lowered. On the other hand, in the top emission type, the circuit element is not disposed between the emission layer and the image displaying surface, and thus, an aperture ratio is enhanced.
FIG. 1 is a cross-sectional view of a related art top emission type organic light emitting display apparatus.
As seen in FIG. 1, a thin film transistor (TFT) T, which includes an active layer 11, a gate insulation layer 12, a gate electrode 13, an interlayer dielectric 14, a source electrode 15, and a drain electrode 16, is formed on a substrate 10, and a passivation layer 20 and a planarization layer 30 are sequentially formed on the TFT T.
An anode electrode 40 and an auxiliary electrode 50 are formed on the planarization layer 30. The auxiliary electrode 50 decreases a resistance of a cathode electrode 80 as will be described below.
A bank 60 is formed on the anode electrode 40 and the auxiliary electrode 50 and defines a pixel area by its absence. An organic emission layer 70 is formed in the pixel area defined by the bank 60, and the cathode electrode 80 is formed on the organic emission layer 70.
In the top emission type, light emitted from the organic emission layer 70 passes through the cathode electrode 80 and travels. Therefore, the cathode electrode 80 is formed of a transparent conductive material, but for this reason, a resistance of the cathode electrode 80 typically is increased. To decrease the resistance of the cathode electrode 80, the cathode electrode 80 is connected to the auxiliary electrode 50.
The related art top emission type organic light emitting display apparatus may have at least the following problems.
The related art organic light emitting display apparatus is an organic light emitting display apparatus to which a top emission type is applied, and has a drawback where it is difficult to deposit the organic emission layer 70. For example, in the related art organic light emitting display apparatus, an additional process may be needed to deposit the organic emission layer 70 on only the anode electrode 40. Also, in a case of blanket-depositing the organic emission layer 70, the auxiliary electrode 50 cannot be connected to the cathode electrode 80. Furthermore, because the organic emission layer 70 is not patterned to be separated in each of a plurality of pixels, defective driving can occur.